This invention relates to a discharge printing procedure on textile stock dyed with indigo blue. This procedure will no doubt revolutionize the textile industry since, to date, it has not been possible to achieve a quality printing on fabrics previously dyed with indigo blue.
One of the basic features of textile stock dyed with indigo blue relates to the degree of setting obtained with this dyestuff. This setting causes problems which have been impossible to solve to date when one wished to achieve a high quality print on fabrics dyed in this way. Up to the present the only achievement has been that of overprinting, i.e. to print the pattern desired over the indigo blue which deteriorated the quality of the print completely. This print disappeared very easily and therefore it was not possible to apply this process to high quality articles.
With the procedure of the present application it is possible to obtain a print with the quality desired, even better than that of the indigo blue dyeing itself and therefore the introduction of the said process is bound to cause a revolution within the textile industry.
With the discharge printing procedure claimed herein, one can achieve perfectly localized discharge effects in the form of fancy patterns on a conventional or knitted fabric previously dyed with indigo blue. This fabric may be dyed only in the warp, only in the weft or on all the yarns. This process can also be applied to non-woven laps, to knitted fabrics or even non-wovens.
The effects of discharge printing can be seen both in patterns in which the basic fabric color normally white or ivory appears and also in colored effects. The number of colors which can be applied is infinite and the geometric form of the patterns is very varied as is also their position on the textile stock.
Furthermore this discharge printing method can be applied to any type of textile fiber which is suitable for dyeing with indigo blue and also to conventional fabrics with any kind of texture and features and to knitted fabrics produced by any kind of knitting method.
The discharge printing procedure to be described here can be applied using any existing printing installation i.e. continuous, discontinuous or jumper.
It is also worthwhile to mention that with this process the initial strength of the fibers or yarns making up the fabrics can be maintained. However, if one needs to change the strength, the process would be adapted to allow this to be done.
Regarding the fastness to washing of the coloring effects achieved by the process claimed herein, this can also be regulated in accordance with any of the degrees of fastness from high to low. Therefore it is quite feasible for the print to have a higher, lower or even the same fastness as the indigo blue dye.
Once the textile stock dyed with indigo blue has been discharge printed, the later finishing stages such as raising, finishing, grinding, ageing can be carried out as well as the application of special chemical finishes such as creaseless finish, unshrinkable finish, mate finish, shiny finish or any other kind of finishing process which may be applied to fabric which has been dyed only with indigo blue.